A compound having a nitrileoxide group is known to be useful as a reaction agent in various applications since it readily click-reacts with an unsaturated bond in other compound ([2+3] cycloaddition reaction). However, the nitrileoxide compound has problems that a reaction such as dimerization readily occurs and the compound is remarkably unstable. For this problem, it is known that a relative stable nitrileoxide compound can be obtained by modifying it into an aromatic nitrileoxide compound having substituents at ortho positions (Patent Literature 1). Furthermore, with respect to this aromatic nitrileoxide, a multifunctional compound can be synthesized. In addition, a polymer can be cross-linked by using this multifunctional aromatic nitrileoxide (Patent Literatures 2-4).